Apparatus and method for supporting distribution from aircraft

ABSTRACT

When distribution material is distributed over a target site on a ground surface from an aircraft, a distribution supporting apparatus offers support information to a pilot dropping the distribution material to efficiently distribute the distribution material. The distribution supporting apparatus includes: an input section to which information items on at least an aircraft velocity, an aircraft altitude, and a wind velocity are input; a computation section configured to compute a location at which the distribution material dropped from the aircraft arrives on the ground surface and a density distribution of the distribution material on the ground surface based on the information items input to the input section; and a display control section configured to display, on a display, the support information relating to the location and density distribution computed by the computation section.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of International Application No.PCT/JP2012/006745 filed on Oct. 22, 2012, which claims priority toJapanese Patent Application No. 2011-232894 filed on Oct. 24, 2011. Theentire disclosures of these applications are incorporated by referenceherein.

BACKGROUND

The present disclosure relates to aerial distribution supportingapparatuses and methods in which when distribution material isdistributed over a target site on the ground surface from an aircraft,support information is offered to a pilot who drops the distributionmaterial to efficiently distribute the distribution material.

Japanese Unexamined Patent Publication No. H08-324499 describes a firehelicopter for dropping a fire extinguishing agent, such as water, fromthe air to a widespread fire, such as a forest fire, or a fire that isdifficult to be sprayed with water from the ground. The fire helicopterincludes an apparatus for supporting the dropping of a fireextinguishing agent. The dropping supporting apparatus functions tocompute the location at which the fire extinguishing agent to be droppedarrives based on information on the aircraft velocity and the aircraftaltitude, and display the computed location superimposed on an imagetaken by a camera. This apparatus facilitates allowing the fireextinguishing agent to reach a fire site on the ground surface.

SUMMARY

Incidentally, in the technique described in Japanese Unexamined PatentPublication No. H08-324499, the location at which the fire extinguishingagent arrives is computed on the assumption that the fire extinguishingagent falls freely.

In contrast, when liquid, foam, or any other material, such as water ora fire extinguishing agent, in, for example, an airborne tank(hereinafter collectively referred to as distribution material) isdistributed over a fire site on the ground surface to extinguish thefire, such distribution material splits into small liquid drops whilefalling, and the liquid drops are dispersed. This allows thedistribution material dropped from an aircraft to be spread over apredetermined area of the ground surface.

Here, studies of inventors of this application have revealed that withincreasing altitude from which distribution material is dropped, thearea of the ground surface where the distribution material is spread(i.e., the distribution area) increases, and the density of thedistribution material on the ground surface (i.e., the amount of thedistribution material per unit length) decreases. On the other hand, thedistribution material having a density higher than or equal to apredetermined density (e.g., 1.6 or more liters of water per squaremeter) is required to effectively extinguish a fire, and for thisreason, when the altitude from which the distribution material isdropped is too high, this is disadvantageous for effectivelyextinguishing a fire.

When the altitude from which the distribution material is dropped islow, the distribution material density increases to help extinguish afire, while the distribution area is reduced to decrease the area wherea fire can be extinguished. This means that the distribution materialmust be dropped many times to extinguish the fire, and the efficiency offire fighting, in particular, for a widespread fire decreases. Adecrease in drop altitude is disadvantageous also in terms of theensuring of the aircraft safety. Furthermore, when the drop altitude istoo low, the distribution material, such as water, reaches the groundsurface in massive form to adversely affect the safety on the groundsurface.

Thus, when distribution material is distributed over a fire site on theground surface from an aircraft, there exists the drop altitude allowingthe area where the distribution material is distributed at a densityhigher than or equal to the distribution material density effective inextinguishing a fire (hereinafter referred to as the effectivedistribution density area) to be largest, and it is most efficient andsafe to perform fire fighting in accordance with the drop altitude. Evenif only the location at which a fire extinguishing agent arrives iscomputed on the assumption that the fire extinguishing agent fallsfreely similarly to the technique described in Japanese UnexaminedPatent Publication No. H08-324499, efficient fire fighting is impossibleunless consideration is given to the drop altitude.

It is therefore an object of the present disclosure to support a pilotto enable efficient and safe distribution of distribution material overa target site on the ground surface from an aircraft.

The present disclosure relates to an aerial distribution supportingapparatus which, when distribution material is distributed over a targetsite on a ground surface from an aircraft, offers support information toa pilot dropping the distribution material to efficiently distribute thedistribution material.

The distribution supporting apparatus includes: an input section towhich information items on at least a velocity and an altitude of theaircraft and a wind velocity are input; a computation section configuredto compute a location at which the distribution material dropped fromthe aircraft arrives on the ground surface and a density distribution ofthe distribution material on the ground surface based on the informationitems input to the input section; and a display control sectionconfigured to display, on a display, the support information relating tothe location and density distribution computed by the computationsection.

Here, the type of the “aircraft” is not limited as long as it is amachine flying through the air, such as a plane or a helicopter. The“distribution material” herein is matter, such as liquid, foam, orpowder, which, if dropped from the aircraft, splits and is dispersedwhile falling to exhibit a predetermined density distribution over apredetermined area when the matter has arrived at the ground surface. Inother words, the distribution material has characteristics correspondingto the altitude from which the distribution material is dropped.Specifically, with increasing drop altitude, the area where thedistribution material is distributed increases, and the distributiondensity decreases, and with decreasing drop altitude, the area where thedistribution material is distributed decreases, and the distributiondensity increases. The distribution material corresponds to, forexample, water or a fire extinguishing agent in a situation where thedistribution supporting apparatus is utilized to extinguish a fire.

The phrase “efficiently distribute the distribution material” means thatthe distribution material is dropped such that the area where thedistribution material is distributed at a desired density is largest.For example, in order to extinguish a fire, water, for example, isdropped such that the area where the distribution material isdistributed at a density enabling the effective extinguishment of a fireis largest.

With the configuration, the information items on at least the aircraftvelocity, the aircraft altitude, and the wind velocity are input to theinput section of the distribution supporting apparatus. Here, the windvelocity may include a headwind/tailwind speed component correspondingto the direction of travel of the aircraft, and a crosswind speedcomponent corresponding to a direction orthogonal to the direction oftravel of the aircraft. The information items correspond to dropconditions on which the distribution material is dropped from theaircraft, and the drop conditions are associated with the location atwhich the distribution material arrives on the ground surface and thedensity distribution of the distribution material on the ground surface.

The computation section computes the location at which the distributionmaterial arrives on the ground surface and the density distribution ofthe distribution material on the ground surface based on the inputinformation items as described above. This means that the location atwhich the dropped distribution material is distributed and the amount ofthe dropped distribution material are grasped.

The display control section displays the support information relating tothe computed location and density distribution on the display.

The support information displayed on the display include informationitems on not only the location at which the distribution materialarrives, but also the density distribution of the distribution materialassociated with the drop altitude of the distribution material. Thus,the pilot drops the distribution material in accordance with the supportinformation displayed on the display, thereby efficiently distributingthe distribution material. The information item on the densitydistribution of the distribution material prevents the drop altitudefrom being lower than required, thereby ensuring the safety of flight.

The distribution material may be water or a fire extinguishing agent tobe distributed over a fire site, an information item on a location ofthe fire site that is the target site may be further input to the inputsection, the computation section may compute, based on the inputinformation items, a drop location and a drop altitude from which thedistribution material is to be dropped and which enable distribution ofthe distribution material having a density higher than or equal to adensity effective in extinguishing a fire over the fire site, and thedisplay control section may display, on the display, information itemson the drop location and the drop altitude from which the distributionmaterial is to be dropped as the support information.

Specifically, assuming that the distribution material has been dropped,the area where the distribution material is distributed at a densityhigher than or equal to the density effective in extinguishing a fire(i.e., the effective distribution density area) and the location of theeffective distribution density area can be computed based on theinformation items, such as the aircraft altitude, input to the inputsection. For this reason, conversely, information on the location of thefire site is identified to enable the computation of the drop locationand drop altitude from which the distribution material is to be droppedand which enables distribution of the distribution material over thefire site at a density higher than or equal to the density effective inextinguishing a fire.

Thus, the computation section computes the drop location and dropaltitude from which the distribution material is to be dropped, and thedisplay control section displays information items on the drop locationand drop altitude as the support information on the display. The pilotmay fly the aircraft such that the aircraft arrives at the drop locationand the drop altitude, and may drop the distribution material at thetime when the aircraft has arrived at the drop location and the dropaltitude. This allows an amount of the distribution material larger thanor equal to the amount thereof effective in extinguishing a fire to bedistributed over as broad an area of the fire site as possible, therebyefficiently extinguishing a fire.

An information item on an aircraft location may be further input to theinput section, and the display control section may display, on thedisplay, an information item on discrepancies between the aircraftlocation and the computed drop location and between the aircraftaltitude and the computed drop altitude as the support information inreal time.

If the pilot views information displayed on the display in real timewhile flying the aircraft to eliminate the discrepancies between theaircraft location and the computed drop location and between theaircraft altitude and the computed drop altitude, the aircraft arrivesat the drop location and the drop altitude. The pilot drops thedistribution material at the time when the aircraft has arrived at thedrop location and the drop altitude, thereby enabling the distributionof an amount of the distribution material larger than or equal to theamount thereof effective in extinguishing a fire over as broad an areaof the fire site as possible. This can reduce the burdens on the pilot,and enables efficient extinguishment of a fire.

An information item on an aircraft location may be further input to theinput section, the computation section may further compute a paththrough which the aircraft reaches the drop location and the dropaltitude, and the display control section may display, on the display,information items on the computed path and a time when the distributionmaterial is to be dropped as the support information in real time.

Specifically, the display control section displays an information itemon the computed path to the drop location and drop altitude from whichthe distribution material is to be dropped as the support information onthe display in real time. The pilot flies the aircraft such that theaircraft travels along the displayed path, thereby allowing the aircraftto arrive at the drop location and the drop altitude. Since the displayfurther displays an information item on the time when the distributionmaterial is to be dropped as the support information, the pilot dropsthe distribution material in accordance with the information item. Thisallows the distribution material to be dropped at the drop location andthe drop altitude, and thus, enables distribution of an amount of thedistribution material larger than or equal to the amount thereofeffective in extinguishing a fire over as broad an area of the fire siteas possible. This can reduce the burdens on the pilot, and enablesefficient extinguishment of a fire.

Here, the apparatus for supporting distribution from the aircraft mayfurther include: a dropper configured to drop the distribution materialwhen the aircraft has arrived at the drop location and the dropaltitude.

Thus, if the pilot flies the aircraft such that the aircraft reaches thedetermined drop location and drop altitude, the dropper automaticallydrops the distribution material. This can significantly reduce theburdens on the pilot, and enables the precise distribution of thedistribution material over the fire site. When not only the requirementthat the aircraft have arrived at the drop location and the dropaltitude, but also the requirement that the pilot allow the dropping,such as the requirement that the pilot turn on a drop switch, aresatisfied, the dropper may drop the distribution material. In otherwords, when the aircraft has arrived at the drop location and the dropaltitude in a situation where the drop switch is on, the dropper maydrop the distribution material.

The distribution material may be water or a fire extinguishing agent tobe distributed over a fire site, the computation section may compute aneffective distribution density area in which the distribution materialis distributed at a density higher than or equal to a density of thedistribution material effective in extinguishing a fire, and a locationof the effective distribution density area, and the display controlsection may display, on the display, the effective distribution densityarea obtained by dropping the distribution material at a present moment,and the location of the effective distribution density area as thesupport information in real time.

Thus, the display displays the effective distribution density areaobtained by dropping the distribution material at the present moment,and the location of the effective distribution density area in real timewhile changing them with the movement of the aircraft. This allows thepilot to drop the distribution material based on these informationitems.

When, for example, a helmet mounted display or a head mounted display(HMD) or a head-up display (HUD) is utilized as the display, the outlineof the effective distribution density area may be displayed to overlapthe view out of the window of the aircraft. The pilot may fly theaircraft such that the visually checked fire site and the displayedeffective distribution density area overlap each other, and may drop thedistribution material at the time when they have overlapped each other.This allows an amount of the distribution material larger than or equalto the amount thereof effective in extinguishing a fire to bedistributed over as broad an area of the fire site as possible, therebyefficiently extinguishing a fire. The display does not need to be theHMD or HUD, and the effective distribution density area may be displayedso as to be superimposed on a map showing, for example, the fire site.

The computation section may compute the location at which thedistribution material arrives and the density distribution based on theinput information items and previously determined table data.

Specifically, the behavior of the dropped distribution material ispreviously analyzed by utilizing, for example, a computational fluiddynamics (CFD) analysis, and information items on the location at whichthe distribution material arrives and the density distribution, whichare based on the analyzed data, are defined as table data together withthe drop conditions on which the distribution material is dropped. Thisallows the computation section to refer to the table data based on theinput information items to calculate the location at which thedistribution material arrives and the density distribution. When aninformation item on the fire site is input, the table data is referredto enable the computation of the drop location and drop altitude fromwhich the distribution material is to be dropped.

Instead of the table data, a model expression obtained by modeling thebehavior of dropped distribution material may be determined, and thecomputation section may compute the location at which the distributionmaterial arrives and the density distribution based on the inputinformation items and the model expression, or compute the drop locationand drop altitude from which the distribution material is to be droppedbased thereon.

The present disclosure also relates to an aerial distribution supportingmethod in which, when distribution material is distributed over a targetsite on a ground surface from an aircraft, support information isoffered to a pilot dropping the distribution material to efficientlydistribute the distribution material.

The method includes: inputting information items on at least a velocityand an altitude of the aircraft and a wind velocity; computing alocation at which the distribution material dropped from the aircraftarrives on the ground surface and a density distribution of thedistribution material on the ground surface based on the inputinformation items; and displaying, on a display, the support informationrelating to the computed location and density distribution.

As described above, in the apparatus and method for supporting thedistribution from the aircraft, a computation is performed on thelocation at which the distribution material arrives on the groundsurface and the density distribution of the distribution material on theground surface, and support information on the location at which thedistribution material arrives and the density distribution of thedistribution material is displayed on the display to allow the pilot todrop the distribution material in accordance with the supportinformation displayed on the display, thereby efficiently distributingthe distribution material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a schematic configuration of afire fighting flying boat.

FIG. 2 is a cross-sectional view of a tank aboard the fire fightingflying boat.

FIG. 3 is a functional block diagram illustrating the configuration of afire fighting supporting apparatus.

FIG. 4 is a diagram illustrating an example screen displayed on an HMDin a water drop area display mode in which the area where water isdropped is displayed.

FIG. 5 is a conceptual diagram of the water drop area display mode.

FIG. 6 is a diagram illustrating an example screen displayed on the HMDin a water drop location display mode in which the location to whichwater is dropped is displayed.

FIG. 7 is a conceptual diagram of the water drop location display mode.

FIG. 8 is a diagram illustrating an example screen displayed on the HMDin a vector display mode in which a vector is displayed.

DETAILED DESCRIPTION

An embodiment of an apparatus for supporting distribution from anaircraft will be described hereinafter with reference to the drawings.The following embodiment is an example. FIG. 1 illustrates a firefighting flying boat 1 in which a fire fighting supporting apparatusserving as a distribution supporting apparatus is used. The firefighting flying boat 1 is utilized to extinguish a widespread fire, suchas a forest fire or an industrial complex fire, from the air, or toprecisely drop water from the air to, for example, a residential area.Although the detailed configuration of the fire fighting flying boat 1is not shown, the fire fighting flying boat 1 is a plane capable ofexecuting takeoffs from both the ground and water and landings thereon,and a middle lower portion of the bodywork of the fire fighting flyingboat 1 includes a tank 11 configured to store water to enable thedropping of water from the air. The fire fighting flying boat 1 isconfigured to taxi on water, such as a lake or sea, to enable theintroduction of water into the tank 11. Foam (a fire extinguishingagent) can be mixed into water in the tank 11.

Here, as illustrated in FIG. 1, the tank 11 includes two tanks includinga front tank 111 and a rear tank 112 that are arranged in afront-to-rear direction of the bodywork. As illustrated in FIG. 2, theinterior of each of the tanks 111 and 112 is partitioned into fourchambers. Lower portions of the chambers of each of the tanks 111 and112 each include an openable/closable door 113. In this example figure,some of the doors 113 are illustrated in a closed position, and theother doors 113 are illustrated in an open position. Separately openingthe doors 113 allows the fire fighting flying boat 1 to drop liquid orfoam, such as water or a fire extinguishing agent, stored in acorresponding one or corresponding ones of a total of eight chambers.Although conceptually illustrated in FIG. 2, the doors 113 each includean actuator 12 configured to open or close the door 113, and a pilotoperates a water drop switch 13 disposed inside the cockpit of the firefighting flying boat 1, thereby allowing the actuator 12 to open orclose a corresponding one of the doors 113. In other words, in the firefighting flying boat 1, the pilot determines whether water is dropped,and determines the time when water is dropped. Although described indetail below, an automatic water drop operation in which the aircraftautomatically drops water, or a semiautomatic water drop operation inwhich on condition that the pilot has operated the water drop switch 13,the aircraft automatically drops water may be used.

The doors 113 of the tank 11 are capable of not only separately opening,but also opening at the same time. The number of the door or doors 113to be opened determines the amount of target water to be dropped.Opening the doors 113 at the same time helps initial fire fighting inwhich, for example, a fire is extinguished intensively at a fire site.Alternatively, the doors 113 can be successively opened. Successivelyopening the doors 113 enables a linear water drop corresponding to theflight path of the fire fighting flying boat 1. This helps form afirebreak. The following description is principally based on the initialfire fighting.

To drop water, the pilot determines the amount of target water to bedropped from the fire fighting flying boat 1. In this determination, forexample, the amount of the target water may be directly selected, or thenumber of the door or doors 113 to be opened may be selected todetermine the amount of the target water.

The capacity of the tank 11 is set at a relatively large capacity of,for example, about 15 tons, thereby allowing a relatively large amountof water to be dropped. Increasing the amount of the target water to bedropped at the same time reduces the spreading of water even in asituation where water is dropped from a high altitude. This can ensurethe effective distribution density effective in extinguishing a firealthough described in detail below. In other words, the altitude fromwhich the fire fighting flying boat 1 drops water can be set at arelatively high altitude. This helps increase the fire fighting safety.

In contrast, with increasing altitude from which water is dropped, thedegree of difficulty in precisely dropping water to a fire site on theground surface increases. To address such a problem, the fire fightingflying boat 1 includes a fire fighting supporting apparatus 2 toprecisely and appropriately drop water to the fire site to increase thefire fighting efficiency. The fire fighting supporting apparatus 2 isconfigured to offer support information on the dropping of water to thepilot.

FIG. 3 is a functional block diagram illustrating the configuration ofthe fire fighting supporting apparatus 2. The fire fighting supportingapparatus 2 includes functional blocks corresponding to an input section21 to which various types of information offered from a bodywork systemof the fire fighting flying boat 1 are input, a computation section 22configured to compute data concerning the support information based onthe input information, and a display control section 23 configured todisplay the support information on an HMD (i.e., a display) 3 worn bythe pilot based on the computation result. The fire fighting supportingapparatus 2 is a computer that has been loaded with software forimplementing the functional blocks illustrated in FIG. 3.

Information items input to the input section 21 are information items onthe aircraft velocity and aircraft altitude of the fire fighting flyingboat 1, the wind velocities (the velocity of wind against the aircraftand the velocity of wind in a direction orthogonal to the aircraft), andthe amount of target water to be dropped that is determined by thepilot. The information items on the aircraft velocity, the aircraftaltitude, and the amount of the target water correspond tospecifications of the aircraft, and the information items on the windvelocities (and wind directions) correspond to atmospheric conditions.The specifications of the aircraft and the atmospheric conditions arerelated to the water drop conditions on which water is dropped. Thewater drop conditions are relevant to effective distribution densityareas and the locations of the effective distribution density areas asdescribed below. The information items are input to the input section 21as needed.

The computation section 22 computes the effective distribution densityareas and the locations of the effective distribution density areasbased on the input information items. Here, the effective distributiondensity areas denote areas of the ground surface where when waterdropped from the fire fighting flying boat 1 has arrived at the groundsurface, water is distributed at a density higher than or equal to apredetermined density. Specifically, liquid, such as water, splits intosmall water drops while falling, and the water drops are dispersed,thereby distributing the water drops over a predetermined area of theground surface. With increasing aircraft altitude from which water isdropped, the area where water is spread increases, and the distributiondensity at which water is distributed decreases. With decreasingaircraft altitude, the area where water is spread decreases, and thedistribution density increases. On the other hand, in order toeffectively extinguish a fire, water having a distribution density of1.6 liters per square meter, or a fire extinguishing agent having adistribution density of 0.8 liters per square meter is required. Such adistribution density is referred to as the effective distributiondensity for extinguishing a fire, and areas of the ground surface wherethe effective distribution density is ensured correspond to theeffective distribution density areas (see also FIG. 5). The inventors ofthis application conducted, for example, an experiment in which water isdropped in a wind tunnel and a computational fluid dynamics (CFD)analysis to verify the behavior of dropped water. This verificationshowed that each of the effective distribution density areas variesdepending on the aircraft altitude from which water is dropped, and thatthere exists the aircraft altitude allowing the effective distributiondensity area to be largest. Furthermore, it was also found that theeffective distribution density areas located to the right and left ofthe point at which water is dropped each have a generally longelliptical shape extending in a direction of travel of the aircraft.

Thus, table data 24 indicating the relationships between various typesof water drop conditions and the size or location of the ellipseindicating the effective distribution density area are created based onthe results obtained from the CFD analysis and the wind-tunnelexperiment, and the fire fighting supporting apparatus 2 allows thetable data 24 to be previously stored in a storage means, such as a harddisk drive (HDD) or a flash memory. The CFD analysis is not limited to aspecific CFD analysis, and an appropriate CFD analysis can be optionallyused.

Each effective distribution density area varies between when water isdropped and when a fire extinguishing agent is dropped. Thus, thestorage means may include table data for the dropping of water and tabledata for the dropping of the fire extinguishing agent. A coefficient maybe added to reference table data (e.g., the table data for the droppingof water) without the storage means including a plurality of types oftable data to compute the effective distribution density areas for thedropping of the fire extinguishing agent.

The computation section 22 refers to the table data 24 based on thewater drop conditions, i.e., the aircraft velocity, the aircraftaltitude, the wind directions, and the amount of target water to bedropped, input to the input section 21 to compute the effectivedistribution density areas (the shape and size of each of the longellipses) and the locations of the areas of the ground surface. Here, asillustrated in FIG. 3, in a situation where drop material typeinformation identifying whether the distribution material is water or afire extinguishing agent is input to the input section 21, when water isdropped, the table data for the dropping of water may be referred to asdescribed above to compute the effective distribution density areas andthe locations of the effective distribution density areas, and when thefire extinguishing agent is dropped, the table data for the dropping ofthe fire extinguishing agent may be referred to compute the effectivedistribution density areas and the locations of the effectivedistribution density areas.

The water drop conditions input to the input section 21 vary as needed.Thus, the computation section 22 performs a computation depending on thewater drop conditions input to the input section 21, and updates theeffective distribution density areas and the locations of the effectivedistribution density areas as needed.

In this example, the fire fighting supporting apparatus 2 includes thetable data 24. However, it may include a model expression obtained bymodeling the behavior of dropped water instead of the table data, andthe computation section 22 may compute the effective distributiondensity areas and the locations of the effective distribution densityareas using the model expression into which the water drop conditionsare substituted.

Although not shown in detail, the HMD 3 is a display which is worn onthe head of the pilot, through which the view out of the window of thefire fighting flying boat 1 is visible, and on which various types ofinformation can be displayed while being superimposed on the view by thecontrol of the display control section 23. The display control section23 changes the contents to be displayed on the HMD 3 depending on theorientation of the HMD 3, i.e., as the view visible through the HMD 3changes with a change in the direction toward which the head of thepilot is oriented.

As described above, the display control section 23 is configured todisplay the support information on the HMD 3, and the supportinformation is displayed in any one of three modes including a waterdrop area display mode, a water drop location display mode, and a vectordisplay mode. Any one of the three display modes may be selected.Alternatively, two or three thereof may be configured, and the pilot mayoptionally select one of them. The three display modes will besequentially described hereinafter.

(Water Drop Area Display Mode)

FIG. 4 illustrates an example display of the support information in thewater drop area display mode. In the water drop area display mode, thedisplay control section 23 displays long ellipses 41, 41 (in thisfigure, partially shown) each indicating the above-described effectivedistribution density area and superimposed on the window view visiblethrough the HMD 3. Furthermore, the display control section 23 displaysa water drop line 42, a water drop altitude index 43, and anintermediate point 44 between the centers of the right and lefteffective distribution density areas. The water drop line 42 shows thedirection in which dropped water falls. The reference character 45denotes an altitude index indicating a minimum safe altitude. Thedisplay control section 23 displays these information items on the HMD 3in real time as the computation section 22 updates the effectivedistribution density areas and the locations of the effectivedistribution density areas whenever necessary as described above. Thedisplay control section 23 changes, for example, the location of theintermediate point 44 with a change in aircraft altitude. The aircraftaltitude at which the water drop altitude index 43 overlaps theintermediate point 44 is an optimum water drop altitude allowing each ofthe effective distribution density areas to be largest. The displaycontrol section 23 further changes the size and location of each ellipse41 with a change in the water drop conditions, such as the aircraftaltitude, and displays the changed ellipse 41 on the HMD 3 (see also theconceptual diagram in FIG. 5).

As such, in the water drop area display mode, the display controlsection 23 displays the location at which if water is dropped at thepresent moment, the water arrives on the ground surface and the areawhere the water is spread, and the pilot can visually recognize thelocation at which the water arrives and the area where the water isspread. For this reason, the pilot views, through the HMD 3, a fire sitethat is a target location to which water is to be dropped while flyingthe fire fighting flying boat 1 such that the fire site overlaps theellipses 41, 41 and such that the water drop altitude index 43 overlapsthe intermediate point 44, and operates the water drop switch 13 at thetime when the fire site and the water drop altitude index 43 overlap theellipses 41, 41 and the intermediate point 44, respectively. This allowsan amount of water effective in extinguishing a fire to be preciselydropped to a large area of the fire site. As a result, the fire can beefficiently extinguished.

Latitude/longitude information on the fire site may be previously inputto the input section 21, and the display control section 23 may allowthe location of the fire site to be displayed on the HMD 3 with asymbol. This allows the pilot to drop water while checking to see therelative position of the symbol of the fire site displayed on the HMD 3to the ellipses 41, 41. The latitude/longitude information on the firesite may be manually input by, for example, the pilot, and specifically,the fire site may be pointed on the window view that is visuallyrecognized through the HMD 3 by, for example, a pointing device toenable the input of the latitude/longitude information on the fire site.Alternatively, the fire site may be pointed on a map to input thelatitude/longitude information on the fire site.

The ellipses 41, the water drop line 42, the water drop altitude index43, the intermediate point 44, and the minimum safe altitude index 45illustrated in FIG. 4 are example indicators for displaying theeffective distribution density areas and the locations of the effectivedistribution density areas. Various display patterns can beappropriately used to display the effective distribution density areasand the locations of the effective distribution density areas.

(Water Drop Location Display Mode)

FIG. 6 illustrates an example display of the support information in thewater drop location display mode. In the water drop location displaymode, latitude/longitude information on the fire site is firstpreviously input to the input section 21, and the computation section 22computes information on the aircraft location (the latitude andlongitude) and the aircraft altitude from each of which water is to bedropped (hereinafter referred to as the water drop target point) asconceptually illustrated in FIG. 7 to effectively drop water to the firesite. Thus, in the water drop location display mode, the display controlsection 23 displays information on the discrepancy between the waterdrop target point and each of the aircraft location (the latitude andthe longitude) and the aircraft altitude as the support information onthe HMD 3.

Specifically, in the water drop location display mode, the location ofthe fire site, i.e., the latitude and longitude thereof, is firstdefined. For this reason, when this display mode is used, information onthe location of the fire site is input to the input section 21.Furthermore, information on the current location of the fire fightingflying boat 1 (i.e., the aircraft location) is also input to the inputsection 21 as needed (see FIG. 3). Here, the information on the locationof the fire site may be manually input, and as described above, theinformation on the location of the fire site may be input by utilizingthe HMD 3 or a map.

As described above, the table data 24 is referred to based on the waterdrop conditions input to the input section 21 to enable the computationof the effective distribution density areas and the locations of theeffective distribution density areas. For this reason, conversely, theaircraft latitude and longitude and the aircraft altitude, i.e., thewater drop target point, from which water can be dropped to the firesite such that each of the effective distribution density areas islargest can be computed based on the defined latitude/longitudeinformation on the fire site. Thus, the computation section 22 refers tothe table data 24 based on the water drop conditions input to the inputsection 21 to compute the water drop target point. Furthermore, thecomputation section 22 computes the discrepancy between the water droptarget point and the current location of the fire fighting flying boat1, i.e., the aircraft latitude and longitude and the aircraft altitude,in accordance with the computed water drop target point. Here, the waterdrop target point is changed with a change in aircraft velocity oratmospheric conditions. Thus, whenever necessary, the computationsection 22 updates the water drop target point based on the water dropconditions input to the input section 21 as needed, and further updatesinformation on the discrepancy between the water drop target point andthe current location of the fire fighting flying boat 1.

In the foregoing manner, the display control section 23 displaysinformation on the discrepancy between the water drop target point andeach of the aircraft latitude and longitude and the aircraft altitude asthe support information on the HMD 3.

In the water drop location display mode, as conceptually illustrated inFIG. 7, a target course and an angle of descent of the aircraft towardthe computed water drop target point are determined, and the firefighting flying boat 1 is guided toward the water drop target pointbased on the determined target course and the determined angle ofdescent of the aircraft. Specifically, in the water drop locationdisplay mode, the display control section 23 displays a flight pathsymbol 61, a steering line 62, and a water drop altitude index 63 inreal time such that the flight path symbol 61, the steering line 62, andthe water drop altitude index 63 overlap the window view visible throughthe HMD 3 as illustrated in FIG. 6. The flight path symbol 61 indicatesthe future location of the fire fighting flying boat 1 determined by thecurrent location of the fire fighting flying boat 1 and information onthe course thereof. The steering line 62 relates to the determinedtarget course toward the water drop target point. The water dropaltitude index 63 relates to the vertical path angle.

In the water drop location display mode, the display control section 23displays a release queue 64 indicating the time when water is to bedropped based on information items on the relative distance between thecurrent location of the aircraft and the water drop target point and theaircraft velocity. The release queue 64 relates to the relative distancebetween the current location of the aircraft and the water drop targetpoint, and thus, can be referred to as information on the discrepancybetween the current location of the aircraft and the water drop targetpoint. The release queue 64 includes a triangular arrow 641 and avertical line 642 along which the arrow 641 moves in this examplefigure. With decreasing distance from the aircraft to the water droptarget point, the arrow 641 of the release queue 64 moves downward, andthe situation where the arrow 641 has reached the lowest end of thevertical line 642 shows that the aircraft has arrived at the water droptarget point. When the fire fighting flying boat 1 arrives within atolerance area where water may be dropped, the display control section23 may allow the release queue 64 to flash, change the color in whichthe release queue 64 is displayed, or allow the release queue 64 toflash while changing the color.

Thus, in the water drop location display mode, the pilot flies the firefighting flying boat 1 such that the flight path symbol 61 overlaps thesteering line 62 and the water drop altitude index 63, and furtheroperates the water drop switch 13 in response to the displayed releasequeue 64. Since, in the water drop location display mode, information onthe discrepancy between the water drop target point and the currentlocation of the aircraft is merely offered to the pilot, the pilot canoptionally determine, for example, the direction of entry into the firesite or the velocity of entry thereinto. Thus, the pilot operates thewater drop switch 13 in accordance with indications of the flight pathsymbol 61, the steering line 62, the water drop altitude index 63, andthe release queue 64 that are displayed on the HMD 3 to enable thedropping of water in the vicinity of the water drop target point. Thisallows an amount of water effective in extinguishing the fire to beprecisely dropped to a broad area of the fire site, and enablesefficient fire fighting. In the water drop location display mode, theoptimum location at which water is to be dropped and the optimumaltitude from which water is to be dropped are previously determined,and while the fire fighting flying boat 1 is guided to the optimumlocation and altitude, the time when water is to be dropped is alsoindicated. This eliminates the need that the pilot visually recognizethe fire site while performing a water drop operation, and thus, reducesthe burdens on the pilot.

In the water drop location display mode, the water drop target point iscomputed, and for this reason, instead of the pilot operating the waterdrop switch 13, the aircraft may output an actuation signal to theactuators 12 at the time when the fire fighting flying boat 1 hasarrived at the water drop target point, thereby enabling automaticdropping of water. Alternatively, when two requirements that the pilothave operated the water drop switch 13 and that the fire fighting flyingboat 1 have arrived at the water drop target point are satisfied, anactuation signal may be output to the actuators 12 to drop water. Inthis case, if the pilot continues pressing the water drop switch 13 inthe vicinity of the water drop target point, water is automaticallydropped when the fire fighting flying boat 1 has arrived at the waterdrop target point. This operation can be referred to as thesemiautomatic water drop operation. Such an automatic water dropoperation or such a semiautomatic water drop operation significantlyreduces the burdens on the pilot while enabling the precise dropping ofwater.

The flight path symbol 61, the steering line 62, the water drop altitudeindex 63, and the release queue 64 illustrated in FIG. 6 are exampleindicators for displaying the discrepancy between the water drop targetpoint and the current location of the fire fighting flying boat 1. Todisplay the discrepancy between the water drop target point and thecurrent location of the fire fighting flying boat 1, various indicationscan be appropriately used.

(Vector Display Mode)

FIG. 8 illustrates an example display of support information in thevector display mode. In the vector display mode, while the computationsection 22 computes the water drop target point in a manner similar tothat in the water drop location display mode, the computation section 22determines the flight path to the water drop target point unlike thewater drop location display mode, and the display control section 23displays the determined flight path as the support information on theHMD 3.

Specifically, in the vector display mode, as described above, theinformation on the location of the fire site and the information on thecurrent location of the aircraft are input to the input section 21, andthe computation section 22 determines the water drop target point andthe flight path to the water drop target point based on the inputinformation. In determining the flight path, the pilot may previouslydesignate the direction of entry into the fire site or the velocity ofentry thereinto.

The display control section 23 displays the determined flight path asthe support information on the HMD 3. As illustrated in FIG. 8, in thevector display mode, the display control section 23 displays a flightpath symbol 81, and displays the determined path in the form of, forexample, a tunnel extending in the direction of travel of the firefighting flying boat 1. Such an indicator is hereinafter referred to asa tunnel 82. The flight path symbol 81 and the tunnel 82 are displayedin real time to overlap the window view visible through the HMD 3. Alsoin the vector display mode, the display control section 23 displays arelease queue 83 similar to that described above.

The pilot flies the fire fighting flying boat 1 such that the flightpath symbol 81 passes through the tunnel 82 at a determined velocity inthe vector display mode. This allows the fire fighting flying boat 1 toarrive at the water drop target point. Simultaneously, the pilotperforms a water drop operation in accordance with the indication of therelease queue 83 as described above. This allows an amount of watereffective in extinguishing the fire to be precisely dropped to a broadarea of the fire site, and enables efficient fire fighting. Also in thevector display mode, in a manner similar to that in the water droplocation display mode, the optimum location at which water is to bedropped and the optimum altitude from which water is to be dropped arepreviously determined, and while the fire fighting flying boat 1 isguided to the optimum location and altitude, the time when water is tobe dropped is also indicated. This reduces the burdens on the pilot.

The automatic water drop operation or the semiautomatic water dropoperation in which the pilot operates the water drop switch 13 may beused as described above without manually dropping water.

The flight path symbol 81, the tunnel 82, and the release queue 83illustrated in FIG. 8 are example indicators for displaying the path ofthe fire fighting flying boat 1 and the time when water is to bedropped. To display the path of the fire fighting flying boat 1 and thetime when water is to be dropped, various indications can beappropriately used.

As such, the fire fighting supporting apparatus 2 offers, to the pilot,not only the location at which, for example, dropped water arrives, butalso information on the effective distribution density areas relating tothe drop altitude. This allows the pilot to precisely and efficientlydistribute, for example, water to the fire site, and helps increase theefficiency of fire fighting. The utilization of the concepts of theeffective distribution density areas prevents the altitude of the firefighting flying boat 1 from being lower than required. This helps ensurethe safety of fire fighting.

The above-described fire fighting supporting apparatus 2 includes theHMD 3 as the display. However, for example, an HUD may be used as thedisplay. Alternatively, map information may be displayed on the display,such as a flat panel display, and the support information may bedisplayed to overlap the map information.

The aircraft including the fire fighting supporting apparatus 2 hereinis not limited to the fire fighting flying boat. For example, a firehelicopter may include the fire fighting supporting apparatus 2.

The distribution supporting apparatus herein can be not only utilized toextinguish a fire at the fire site but also broadly utilized todistribute distribution material, such as liquid, foam, or powder, tothe ground surface from an aircraft. In other words, cases wheredistribution material should be efficiently distributed are not limitedto fire fighting. Examples of such cases include various operations inwhich distribution material is dropped from an aircraft, such as anoperation for distributing chemicals, such as agricultural chemicals, toa broad area. The concepts of the effective distribution density areascan be applied to such operations. The effective distribution densityareas vary depending on, for example, the type of distribution materialand the purpose of the distribution. In other words, the distributionsupporting apparatus herein can be utilized to distribute, for example,chemicals.

As described above, the apparatus and method for supporting distributionfrom an aircraft herein enables the efficient distribution ofdistribution material, and can be utilized for fire fighting for, e.g.,a forest fire or other various distribution operations.

What is claimed is:
 1. An aerial distribution supporting apparatuswhich, when distribution material is distributed over a target site on aground surface from an aircraft, offers support information to a pilotdropping the distribution material to efficiently distribute thedistribution material, the apparatus comprising: an input section towhich information items on at least a velocity and an altitude of theaircraft and a wind velocity are input; a computation section configuredto compute a location at which the distribution material dropped fromthe aircraft arrives on the ground surface and a density distribution ofthe distribution material on the ground surface based on the informationitems input to the input section; and a display control sectionconfigured to display, on a display, the support information relating tothe location and density distribution computed by the computationsection.
 2. The apparatus of claim 1, wherein the distribution materialis water or a fire extinguishing agent to be distributed over a firesite, an information item on a location of the fire site that is thetarget site is further input to the input section, the computationsection computes, based on the input information items, a drop locationand a drop altitude from which the distribution material is to bedropped and which enable distribution of the distribution material overthe fire site at a density higher than or equal to a density effectivein extinguishing a fire, and the display control section displays, onthe display, information items on the drop location and the dropaltitude from which the distribution material is to be dropped as thesupport information.
 3. The apparatus of claim 2, wherein an informationitem on an aircraft location is further input to the input section, andthe display control section displays, on the display, an informationitem on discrepancies between the aircraft location and the computeddrop location and between the aircraft altitude and the computed dropaltitude as the support information in real time.
 4. The apparatus ofclaim 2, wherein an information item on an aircraft location is furtherinput to the input section, the computation section further computes apath through which the aircraft reaches the drop location and the dropaltitude, and the display control section displays, on the display,information items on the computed path and a time when the distributionmaterial is to be dropped as the support information in real time. 5.The apparatus of claim 3 further comprising: a dropper configured todrop the distribution material when the aircraft has arrived at the droplocation and the drop altitude.
 6. The apparatus of claim 1, wherein thedistribution material is water or a fire extinguishing agent to bedistributed over a fire site, the computation section computes aneffective distribution density area in which the distribution materialis distributed at a density higher than or equal to a density effectivein extinguishing a fire, and a location of the effective distributiondensity area, and the display control section displays, on the display,the effective distribution density area obtained by dropping thedistribution material at a present moment, and the location of theeffective distribution density area as the support information in realtime.
 7. The apparatus of claim 1, wherein the computation sectioncomputes, based on the input information items and previously determinedtable data, the location at which the distribution material arrives andthe density distribution.
 8. An aerial distribution supporting method inwhich, when distribution material is distributed over a target site on aground surface from an aircraft, support information is offered to apilot dropping the distribution material to efficiently distribute thedistribution material, the method comprising: inputting informationitems on at least a velocity and an altitude of the aircraft and a windvelocity; computing, based on the input information items, a location atwhich the distribution material dropped from the aircraft arrives on theground surface, and a density distribution of the distribution materialon the ground surface; and displaying, on a display, the supportinformation relating to the computed location and density distribution.